Question

The cavity of the blind riser is  ______________

(a) Square

(b) Desired shape

(c) Round

(d) Rhombus

I had been asked this question in an internship interview.

This intriguing question comes from Types of Risers topic in section Concept of Gating and Risering of Foundry and Forging

Answer 1

The correct option is (c) Round

To explain I would say: A blind riser is a rounded cavity and it represents the minimum practical ratio of the surface area to the volume and thus associates a slow cooling rate. It is more efficient to use a round shaped blind riser.